As personal computers go multi-media, many electronics companies try to redefine the computers as home entertainment centers. In the coming years, personal computers may gradually merge with televisions. Displaying picture data generated by a computer on a television with both high quality and good resolution is an important issue that many computer manufacturers are working to resolve.
Traditionally, the picture data generated by a computer system are stored in a VGA card in an RGB format before being displayed. The format used in a television system is, however, either YIQ for NTSC standard or YUV for
standard. Conversion in the format is required if the data are displayed on a television. When the picture data from a computer are displayed on a television, flickers that are not only annoying but also harmful to human eyes often occur due to the fact that only every other line is displayed.
The flickers are, generally, the consequence of under-sampling effect introduced during the conversion of computer picture data to television picture data. One approach to reducing the flickers is to apply a low-pass filter to the picture data after the format conversion and before the data are displayed. This approach blurs the whole picture data. Therefore, the pictures displayed on a television may have less flickers but their resolution is also greatly reduced throughout the whole pictures due to the blurring effect. The quality of the pictures shown on the television is degraded.